Patronuses and Proof

[potioncat]

Sigune wrote: 
> Could it be that the shape of Snape's Patronus will provide a key to 
> his allegiances in Book 7? If I am not mistaken, JKR has politely 
> declined to reveal the shape of Snape's Patronus because 'it would 
> give too much away'. Might not this shape rather than bottled 
> memories be proof of where Snape's loyalties really lie? If the 
> killing of Dumbledore was forced on him against his own will, and his 
> look of loathing was not directed at Dumbledore but at his own deed, 
> then in all probability the death has affected him deeply - deep 
> enough to change the shape of his Patronus into, say, a phoenix... It 
> could be in preparation of this kind of revelation that we have been 
> shown Tonks' Patronus change on the basis of deep emotion.
>

Potioncat:
First JKR tells us (at the last moment) that a Patronus is distinctive 
and unique, then she shows us Tonk's "new" Patronus. She does this 
without telling us what it is or what it had been. Of course, knowing 
Snape, it might be that it wasn't Tonks, but someone else; or that he 
knew both Patronuses and preferred the earlier one; or that this one 
looks weaker than the one she used to summon. Who knows!

But we're told Dark Magic can't be used on them and they can't be 
counterfitted....so it would seem that if Snape's Patronus showed up, 
it would be recognised. Would it be proof that Snape was a good guy, or 
seen as proof that he is a powerful Dark Wizard who can manipulate 
Patronuses?

Everyone's immediate doubt of Snape reminds me of how quickly everyone 
believed Sirius was the spy. I think this group of wizards jumps to 
ESE! conclusions faster than we do.
Kathy W.